Juji jime

This is a family of three closely related chokes. These
seem to be "simple" chokes, but I still have a
lot of difficulty pulling them off.

In these chokes, you grip your opponent's collar so that your
wrists cross in front of your opponent's neck. Pressure is applied with
the collar and/or your hands to the sides of the opponent's neck. The
difference in the three chokes is in how the hands are turned and that tends to
drive the steps necessary to apply them.

Gyaku Juji Jime

"Reverse cross choke." This one is executed with you
gripping the collar so that your palms are away from your opponent's neck.
The back of your hands face your opponent.

To execute this choke, reach along the opponent's collar,
grabbing it as far back as you can. Pull toward you and across, applying
pressure to the sides of your opponent's neck with the backs of your
hands. I find it works a bit better if you twist your hands slightly so
that the knuckles run across the neck and apply the pressure. If you're on
your back, with your opponent above you, you can use your legs to push your
opponent's legs back, adding force to the choke.

Nami Juji Jime

"Normal cross choke." This one is executed with you
gripping the collar so that your palms face toward your opponent's
neck/shoulders.

Kata Juji Jime

"Half cross choke." This one is executed with you
gripping the collar so that one palm is facing away from your opponent and one
plam is facing toward his neck/shoulder.